The Sudbury Neutrino Observatory (SNO) detector is a heavy-water Cherenkov detector designed to detect neutrinos produced by fusion reactions in the Sun. It consists of 1000 tons of heavy water contained in a 12-meter diameter acrylic vessel. In order to reduce cosmic-ray-induced backgrounds, the detector is located 6800 feet underground, in a working nickel mine near Sudbury, Ontario, Canada. SNO has recently stopped data acquisition (November 2006), having successfully solved the solar neutrino problem.
After the heavy water has been removed, the acrylic vessel will be filled with liquid scintillator for the SNO+ experiment. Transforming SNO into a liquid scintillator detector will boost the light yield by more than a factor of 50 and protons will replace deuterons as the principal neutrino target. SNO+ will preserve the excellent supernova neutrino sensitivity via charged-current and neutral-current reactions on both protons and carbon. Additionally, a liquid scintillator could serve as the medium in which a competitive, next-generation neutrinoless double beta decay search (SNO++) could be carried out.
This proposal seeks funds for a group at ISU to conduct developmental studies to optimize calibration methods and low-level background monitoring for SNO+, to investigate methods of monitoring calibration source positions, and to explore the possibility of using 150Nd in the liquid scintillator to search for neutrinoless double beta decay (SNO++). Funds are also sought to provide for ISU's continued efforts as part of the SNO+ collaboration, specifically with the calibration group.
Broader Impact This proposal will provide opportunities for Idaho State University undergraduate and graduate students to participate in a world-class international collaboration in a truly unique setting. Methods developed such as improved background monitoring techniques may be useful for SNOLAB and future underground laboratories. Techniques explored during the 150Nd studies may also prove useful for future experiments, given the difficulty in acquiring such enriched isotopes.
